Bell Communications Research Inc, the research arm belonging to the Baby Bells, has developed a semiconductor laser replacement for the bus clock currently used to synchronise everything in a computer, and claims that it will bring the operation of the entire system much closer to the rated capability of the chips used – at present the bus clock has to be slowed to take account of the delay in signal transmission along copper connections to remoter parts of the computer. The phase-locked laser oscillates at 120pS, and the light it emits is split into as many as 1,024 separate beams using a star coupler, each of which can be sent down a fibre optic link to a different component. Bellcore is saying that it will enable systems to operate 10 times as fast as they do today and could be ready in five years.
